Likely culprit for harshness at higher volumes?


Hi,

I'm a newbie to higher end audio. I have a very modest system:
1) Pre-amp: Anthem AVM2
2) Amp: Adcom GFA-5400
3) Source: Sony CDP-X111ES CD player
4) Speakers: KEF C75
5) Toslink between source and pre-amp; cheap RCA cables from pre-amp to amp; 16 or 18 gauge speaker wire (Radio Shack?)

Room setup (10-ish feet x 20-ish feet rectangle):
1) 2 foot deep cabinets along one wall (20-ish foot)
2) Components stacked on top of small end table against rear wall (10 foot); centered between cabinets and opposite wall.
3) Speakers slightly in front of end table and about 2 feet from side walls and 4 feet from rear wall

Sounds good at about -45 to -25db; but higher frequencies get harsh at higher than -25db.

Appreciate your thoughts.
saru
Hi there,

Sorry, I missed that. I'm in northern CA in the outskirts of the Bay Area. It's relatively inconvenient except for the neighboring cows. :) Folks have been more than kind offering suggestions here on the forum, especially given my very modest system (My AVM2 may be the only unit worth mentioning and that's more than 10 years old).

The sound has actually improved dramatically since the thread started. I've actually to the point of indifference to the original issue that prompted me to start this thread (is not completely gone but it's approaching acceptance).

My I've noticed that the onion peeling has started. With relief of the original problem has come new 'concerns.' For example:

1) I'm now able to notice noise / hiss in what I believe is the content (for example, a track may start fine with just vocal and no instruments, but when the instruments start to kick in, I hear some background hiss / white noise).

2) I now realize that, whatever the musical merits of Miles Davis' Kind of Blue (Columbia 20-bit remastered version), I now notice what seems to be distortions at points in several tracks -- especially noticeable in the first few minutes of the first track. At least the sounds are not recognizable as any instrument I've heard before.

3) Something in my system / room is causing the low end to seem muffled (using the KEF C75) and poorly imaged. It's like basses span the soundstage are played behind a thick curtain. Still playing around with this. Here is one area where it would really help to have some known good content - I need to follow-up on some of the suggestions above, including getting the headphones that almarg recommended.

Sorry about my volume references -- this is still new to me and not sure how to describe stuff quickly.

I'm not trying to listen at painful volume levels -- I think I was just noting that the earlier harshness has seemed to move to these louder levels (at which I'm also noticing some additional non-musical sounds). Whereas the harshness that prompted this thread was at listening volume levels (where I can hear background instruments and where I start to feel enveloped in the music -- really hard to describe this -- it's as though music is a point source in the room at lower volumes, while at 'listening' volumes the music seems to fill the room and you feel like you're a part of it.

So, at this point, I think I've reached a point of acceptable resolution for the initial problem (still will continue to tweak) but and somewhat shifting focus to cheap, significant improvements to sound quality.

The sound quality seems to be the same between using toslink to my ARM2 (Burr Brown 24/96 DAC per the manual) and using analog (switching from 'digital' in Disc 1 to 'analog' on Disk 2 is seamless). So, based on what I've been learning so far, unless the AVM2 is generally considered a poor DAC/pre, this seems to suggest I should be looking at my amp or speakers (discounting the room once I get the headphones).

It's mostly academic at this point as I probably couldn't afford to replacing anything with something better. But, I'd like to isolate the issue so that I can keep an eye out for a bargain with the right attributes to make significant improvements to the listening experience. As I don't think I'm in the realm of diminishing returns yet, I think I can viably improve the quality w/out large net expenditures. At least I hope this is the case. :)
I was going to suggest the long wall placement, but it sounds like you've discovered this already. A room with lots of reflective surfaces can cause the sound to harden as the volume is increased, so you want to get the speakers away from walls as is practically possible.

For the bass issue, try moving the speakers closer or further away from the wall a couple inches at a time.

I have that "20-bit" KOB issue, and it does have a lot of distortion. Maybe someone can comment on the gazillion other KOB reissues.

As for hiss, it sounds like your system is just letting you hear what's on the recording. You might experiment with your tone controls on these recordings.

Thanks -- yes, I'm finding that small changes in speaker placement can dramatically change the experience. I'm overwhelmed by the number of degrees of freedom here: x,y,z,separation, toe-in, etc.

Seems like there should be a computer model that incorporates room dynamics via camera and microphone. Too complicate for us mere mortals. :)
There are some computer programs like that, but I'm not sure how sophisticated they are. I think real rooms -- sheetrock vs. plaster vs. concrete, suspended floors, alcoves, heating ducts, furniture, doors, hallways, etc -- would pretty much confound the results.